Cancerous lesion at vaccination site is uncommon

Injection-site sarcomas, also known as vaccine-associated sarcomas, are rare and not a reason to forgo feline vaccinations, writes veterinarian Lee Pickett, who says the incidence of such tumors is 0.5 to 2 per 10,000 vaccinations. The risk of contracting diseases vaccines protect against is a much greater concern, Dr. Pickett argues.